Method of and apparatus for generating producer-gas.



E. SERVAIS. METHOD OF AND APPARATUS FOR GBNERATING EODUGER GAS.

APPLIATIN FILED PERM, lQlS.

Paenteu 'June 2, 19ML smtrns LEEIANUL SRRVAIS,F LXBIIBUGS'fLU-XIMB'URGL METHOD F ANDf-APQARATUS FOB GENERATINGPRODUGER-GLS.

' ispecitionofmtersletent. t -Patdnted Tuneigqlgigg Y Application-flied February 24,1913. Seril'Nd 7506329;

l To all whom it may concern:

Be itknown that I, lEMMANUEL" SERVAIS, a citizen 'ofthe Grand' Duchy of Luxemburg, residing at Luxemburg, in the Grand Duchy of Luxemburg, have invented `certain new and useful Improvements in the Methodof and Apparatus for VGenerating Producer-Gas for Power and Heating Purposes, of-which the vfollowing is a 'speci` cation.

This invention relates to-the manufacture 'of producer-gas for power and heating purposes, performed 4with discharge of the slag in a liquid state and the object of the invention `is to provide means whereby the production of gas; from fuel, more particularly from inferior lfuel such as coal-waste, coke-1 waste,' brown coal Vor lignite, 'can be performed without prelnatilre` formation of slag in the charge, liable tocause obstruction; and with security of maintaining the slag in a liquid state in theslag pan, from 4which it can bedrawn off freely Vatintervals.y `v In--connection with gas-producers` clischarging liquid slag, that is to say producers working with blast, it is found that 'obstructions by slag are particularly liable to` occur above the twyers' admittmg the blast. Arches are formed 'in'the charge, whichlpreventfaccess of fresh' fuel .to the tw-yers; The blast sweeps through: the upper' layers and causes combustion, whereby liquid is formed,'whichflows downward toward the colder blast and solidiies, causing obstruction. According to the present in- /vention this is prevented by restricting the melting of the ash to the twyer zone, the charge abovethis Zone being 'cooled to a temperature below that at which slag-is formed, the cooling being eiected by introduction of gases or vapor, for example, steam or 'carbon dioxid, the decomposition of which absorbs heat.

- 'The proper temperature for the fuel is ascertained by taking the temperature of thegases issuingl from. the generator, and this3 latterv temperature depends on the nature of: the fuel used. In'the case of 'fuel contain! ing volatile constituents or much water, .the

temperature ofthe gasv is low, sometimes even under 10000., whereas in thevcase of coke and fuel with a low percentage of volatile constituents,-such "as anthracite,

. the gas gnlly'at a temperature between 450 and The-cooling fof the charge, as indicated is notinv itself suilicie'nt to allow of continuous working of the generator. In orderto allowfof such working it must-be possible to draw fllthe slag atLint-ervalsv in a thin l1qu1d state. Slag 1s a 'had heateonduetor, and 'the slag Ahearth is cooled by 'radiation and conduction, so that a solid-crust of slag is liable'to beI formed on the bottom and walls thereo-'Whereby the-opening vof `the gateis'rendered difficult. As ther-thickness of the crust on the bottom'increases, the outlet hole must be made at a higher 1evel,and ultimately there is risk of' slag entering the twyers 'and stopping the' work. `To prevent this incrustation I heat Ythe-hearth externally.` Though this does not`increase the temperature 'of-the slag, whichl is not necessary, it prevents such dierence'of temperal ture between the contents of the hearth and its surroundingsias is liable to `cause `solidification of slag. i

' From'the fact that slag is liable to solidify on 'the bottomand walls it is clear that the 1 temperature 'of the-slag bath is not uniform throughout the bath. The action of the external heating in preventing incrustation, can accordingly be assisted by providing for uniform distribution of heat in the bath, and this can be done by' continuouslyagitating the bath. For this purpose I use the blast, arranging twyers downwardly7 andlaterally inclinedso that they deliver the blast in a manner which causes circulation of the bath.

It has been observedthat solidification of V*the slag becomes more rapid as the slag approaches the blast,from which it appears that the blast favorssolidification. -I attribute this solely to the coldness of the air blown into' the generator. Hot blast, directed as described on to the bath, produces jets of flame which impinge onthe bath and furtherred-uce the tendency to`solidication of the slag. Inferior fuels, such as coke IduSt, inai divided state, and lignite which breaks up 'when gas is evolved therefrom, -have heretofore" been made linto' briquets prior to use in a generator'dischargingliquid slag, as otherwise the blast makes channels sides of thel generator.

through the charge, and causes carbon dioxid to be produced instead of carbon monoxid, or even leaves free oxygen in the gas. lVith my invention thc cost of briqueting can be saved, because the steam vapor or gas introduced above the twyers, for cooling the charge, maintains the more or less divided fuel in a loose state, owing to absence of` fort mation of slag, and channels formed by the blast are vquickly broken .down by the steam or gas entering under pressure. The maintenance of the charge in a'loose state by the gas or steam, as described, also obviates the necessity for poking or raking the charge. It is found that the tendency to formation of channels by the blast is greatest at the Accordingly it is found advantageous to give the steam inlet ports a lateral inclination, so that the steam sweeps in a more or less tangential or chordal direction. This arrangement'also increases the uniformity of the mechanical effect. of the steam, over the cross-section of the charge, and prevents dead corners, more especially at the sides, where theA formation of slag is most dangerous, as adhesion of slag to the walls obstructs the descent of the charge.

`In producing gas from fuel of low specific weight, for example cokev dust, it is found that some fuel is carried upward by the stream of gas and is withdrawn from the zone of combustion. This is more part-icularly the case when working with abundant blast at comparatively high pressure. I overcome this difficulty by more or less sat-- urating the fuel with milk of lime, whereby the fuel is rendered sufficiently heavy to prevent it from being carried upward by the blast. The milk of lime also has a favorable efl'ect on the composition of the slag. The hydrate of lime does not give' off its water until a. high temperature is obtained, but then the water is in part decomposed and enriches the gas. Though I primarily intend the addition of milk lof lime for use with light fuel which is in adivided state or is liable to crumble, I may use the same withany other kind of fuel which is porous or capable of absorbing the liquid.

An important factor in regard to free Withdrawal of liquid uniformity of the composition of the slag, as the melting point depends on the composition. Diiiiculty has heretofore been encountered in this respect and this I attribute to the fact that some flux, such as limestone. `has been used to .make the ash melt, and the melting only takes place where the flux is brought into contact with ash at the requisitev temperature. Clearly it is essential to have a' proper mechanical mixture of flux and ash, in order that no solid lime- Istone may pass down into'the hearth, and thus be withdrawn from action on the ash slag at intervals is the and cause variations in the chemical composition of the slag, rendering the latter at times viscous and at times thin. Moreover, the proportion of ash varies at times, so that the mere addition of a flux such as lime-stone cannot result in a uniform product, because the requisite quant-ity of flux cannot at all times be known. In practice it is impossible to insure uniformity by taking samples of the slag and analyzing the same. I meet this difficulty by using tinished slag as a iux, thecomposition of which comprises lime, alumina, silica, etc., like the slag discharged from the generator, the lime belng in such proportion as to enable the slag to perform the function of the llime-stone heretofore used. A slag suitable for this purpose is blast-furnace slag. The silica in the ash combines with part of the lime in this slag,`and the remainder of the lime, together with the silica, alumina, etc., in the blast-furnace slag, is drawn off with the generator slag. `This addition forms a kind of regulating factor in regard to the composition of the slag, so that the variations in quality are slighter than if limestone or the like is used as flux. The'slagflux melts at a temperature below that at which slag is formed, and its melting is not dependent on cont-act with another ingredient of the charge. Whereas, in case of some irregularity in the charging or the like, some lime-stone would pass unmeltedinto the slaghearth, the slag-flux under the same conditions melts and carries with it some ash into the hearth, melting the said ash, and the remainder of the ash, falling unmelted into' the hearth, encounters there sufficient lime to cause it to melt.

Another advantage of using blast-furnace slag as a flux vlies in the fact that the slag entering the hearth is always at the same temperature, and the amount of slag obtained per unit of time is considerably greater'than if lime-stone is used as uX. The temperature of the bath is much more uniform.

Apparatus for working according to my improved process is shown in the accompanying drawings, in which- Figure l is a vertical section thereof, and Fig. 2 a cross section on the line 2-2 of Fig. 1.

In the drawing 1 designates the generator, at the top of which is a charging hopper 2,

' With lid 3 and bell valve t controlled by a lever 5. In the lower part of the generator there is a cooling zone a, into which steam is admitted by means of nozzles G connected to a steam pipe 7. Instead of steam, I may use other vapor or gas the decomposition of whichv absorbs heat, that is to say causes part of the heat to become latent. ready mentioned the nozzles 6 are preferably laterally inclined, z'. e. tangential toan (through a gate 10 into a trouglh 11.

ima "nary horizontal circle in the enerator, in t e same manner as shown 1n 1g. .2 for the blast twyers 8. Below the zone a 1s the combustion zone b, into which extends the` twyers 8 connected to the blast lpipe 9. Below the combustion zone is t e hearth c for the slag, the slag beino' discharged As shown in Fig. 1 the axes w, of the twyers 8 are downwardly inclined to the horizontal lane y-y below the twyers, so that the blIfi-st impinges on the slag bath. As shown in Fig. 2, in which e 'e is a radial line from the center of the enerator, the axes w are also laterally inc ined, or tangential to a circle within the generator, so that the blast produces a kind of eddy, as indicated by the arrow w, and the slag bath is maintained in constant circulation, whereby solid constituents thereof, if accidentally present, are quickly reduced to a liquid state, and the bath is rendered uniform i throughout in its composition. Below the convex door 12 of the slag-pan there is a heating chamber 13, to which combustible gas is supplied by a pipe 14, and air by pipes 15, the products of combustion being carried to a chimney by a flue 16. The nozzles 6 and twyers 8 may be cooled bv water, but means for this purpose are not s own in the drawing. The air supplied to the blast pipe 9 passes through a heater 17, through which the gas produced in the generator passes on its way from the eduction pi e 18 to the gas pipe 19. |The cold air for lasting the generator flows from a pipe 20 into the heater 17, and passes in the latter around the vertical passages 21 through which the producer gas Hows, the heated air then passing through a pipe 22 to the pipe 9, and twyers 8.

ln operation, the producer is kept continuously charged with a suitable quantity of carbonaceous fuel mixed with a suitable flux, if desired, the lower portion of the charge being maintained at a gasifying temperature by blasts of heated air injected through the twyers 8. Theintense heat causes combustion of the fuel, the heat produced being sutlicient to completely gasify the carbonaceous portion of the charge and to melt the mineral ingredients, the molten material collecting in the hearth C. In order to prevent fusion above the zone of the twyers, a sufficient quantity of steam or other endothermically decomposable gas or vapor is introduced through the twyers 6.

its by my invention, ample provision is made for taking care of the slag produced, the high temperature, .above 1000o C., required for the complete formation of carbon monoxid, may be continuously maintained. As the charge is kept below the slag fusion temperature until the zoneincandescence at the twyers is reached, there is no danger of elinkering, and the free carbon is completely gasiiied. When the charge reaches the neighborhood of the twyers, the slag-forming ingredients are 'completely melted, and, by my method of heat`n the slag-hearth, are maintained in ilui condition until tapped from the producer.

What I claim is:

1. An improvement in the manufacture of gas in a gas producer, which consists in mamtaining a gasifying temperature at the lower portion of the fuel charge by a blast of air introduced through twyers, cooling the charge above the twyers to a temperature below that of slag fusion by introducing thereinto a gas or va or which decomc poses with absorption o heat, permitting molten slag to accumulate on a hearth below' the twyers, and supplying additional heat to the slag to prevent solidilication thereof.

2. An improvement in the manufacture of gas in a gas producer, which consists in 2 maintaining a gasifyingtemperature at the lower portion of the fuel charge by a blast l`of air introduced through twyers, cooling vthe charge above the twyers to a temperature below that of slag fusion by introducing thereinto a gas or vapor which decomposes with absorption of heat, ermitting molten slag to accumulate on a earth below the twyers, and maintaining the slag in molten condition by heating the hearth.

3. An improvement in the manufacture of gas in a gas producer, which consists in maintainin a gasifying temperature at the lower portion of the fuel charge by a blast of air introduced through twyers, cooling the charge aboveA the twyers to a temperature below that of slag fusion by introducing thereinto a gas or vapor which decomposes with absorption of heat, permitting molten slag to accumulate on a hearth loelow the twyers, maintaining the slag in molten condition by heating the hearth, and agitating the slag bath by causing the heated blast to .impinge thereon.

4l. ln a method of manufacturing gas in a gas producer by maintaining a gasifying temperature at the lower portion of the charge by a blast of air introduced through twyers, the step which consists in injecting a gas o-r vapor, which decomposes with absorption of heat, chordally into thecharge above the blast twyers, thereby maintaining the charge below the temperature of slag fusion and preventing the formation of channels therein.

5. The method of manufacturin gas in a gas producer, which consists in a ding to the fuel a preformed slag liux having a meltin -point below the temperature of fun sion o the fuel-ash, maintaining a gasifying temperature by a blast of air introduced through twyers at the lower portion of the l charge, cooling the charge above the twyers to a temperature below that of slag-fusion by introducing thereinto a gas or vapor which decomposes with absorption of heat, and permitting molten slag to accumulate on a hearth below the twyers.

6. The method of manufacturing gas in a gas producer, which consists in adding to the fuel a slag fiux havin a melting-point below the temperature of usion of the fuelash, maintaining a gasifying temperature by a blast of air introduced through tw. ers at the lower portion of the charge, coo ing the charge above the twyers to a temperature below that of slag-fusion by introducing thereinto a gas or vapor which decomposes with absorption of heat, permitting -molten slag to accumulate on ahearth belov:r the twyers, and supplying additional heat to the slag to prevent solidification thereof.

7. In a gas-producer operating with discharge of liquid slag, the combination of blast twyers, means for injecting gas or vapor into the charge above said twyers, and means for supplying heat to the slag below said twyers.

8. In a gas-producer operatin with discharge of liquid slag, the com ination of blast twyers, with nozzles located above said twyers for introducing gas or vapor into the charge, the axes o f said nozzles being tangential to a circle within the'producer.

9. In a gasproducer, a shaft, twyersV for injecting air located in the lower portion of the shaft, a slag hearth beneath the twyers, and means for continuously supplying heat to the exterior of the slag hearth to maintainthe fluidity of the slag therein.

l0. In a gas producer, a shaft, twyers for injectin air located in the lowerv ortion of the sha t, a slag hearth beneath tile twyers, and means for externally heating the slag hearth.

11. In a gas producer, a shaft, twyers for injecting air located in the lower portion of the shaft, and a slag hearth beneath the twyers, said twyers having their axes downwardly and laterally inclined.

12. In a gas producer, a shaft, twyers for injecting air located in the lower portion of the shaft, a slag hearth beneath the twyers, said twyers havin their axes downwardly and laterally inc ined, and means for heating the exterior of the slag hearth.

In testimony whereof I affix my signature in presence of two witnesses.

EMMANUEL sERvAIs. [1. a]

Witnesses HELEN N UFER, ALBERT NI'JFER. 

